I got an email from the Amazon HR to know about my skills and have a quick discussion about the opportunity. The interview process was spread over 3 weeks for just 2 calls which is a lot of waiting.. One setting up some time, the HR went through the resume and asked general questions. At the end of the call, the HR asked me if I would be willing to answer a couple of technical questions. I said yes sure and she asked me about basic data structures. She told me to brush up on DS and algorithms. After 1 week, I got another email from the hiring team HR and she asked for 5 different time slots to setup a technical discussion. I had a call with the Technical manager and he explained about the company, team size and his requirement. The upon clearing the basic Android questions, I was given a code writing challenge with the coin problem question. After a bit of hint, I was able to complete it. But the interviewer was expecting an answer as I've just graduated from College.